Connect Your Business Number to an AI Phone Assistant

There are three ways to connect your existing business number to an AI phone assistant without changing it: call forwarding (the operator passes calls on to a number the assistant is connected to), connecting over a SIP trunk (the line stays with your operator while calls reach the platform over the internet, an approach known as BYOC) and number porting (the number moves to a new operator). The lowest-risk start is usually to forward only busy and unanswered calls; for a permanent setup, BYOC or porting is the better fit.

This guide is written for numbers in Turkey. We cover how the type of number affects your options, the layers a call passes through, steps for a switch without downtime, what to test before going live and the problems you are most likely to run into.

Start with your number

Which method you can use depends largely on the type of number and the operator that assigned it.

• Landline (geographic) numbers: Numbers with an area code, such as 0212 or 0312. They are linked to a province or region, and most operators offer forwarding and SIP options for them.
• 0850 numbers: The Turkish regulator BTK defines location-independent numbers as numbers that have no geographic meaning and are used for location-independent services. BTK allocates them to operators in blocks, so your business's 0850 number lives on the infrastructure of the operator you got it from.
• 444 numbers: Seven-digit business numbers that can be dialled from anywhere in Turkey without an area code. Ask the operator that assigned the number about forwarding, SIP and porting; the conditions can differ from other number types.
• Mobile numbers: Numbers starting with 05. Because the line is tied to a SIM card, forwarding is usually the most practical route.

Number porting in Turkey is governed by BTK's Number Portability Regulation (in Turkish). Under the regulation, geographic, non-geographic and mobile numbers are all within the scope of portability; operator porting takes place between fixed networks, or between mobile networks. The process starts when the subscriber applies to the new (recipient) operator and cannot be started without the subscriber's request. The regulation has been amended since it was published in 2009, so check the current text and your operator for detailed timelines and conditions (last checked: 22 October 2026).

Three ways to connect

1. Call forwarding

Call forwarding means the operator passes calls to your number on to another number. There are four types: unconditional (every call), on busy, on no answer and when unreachable. The forwarding target is a number the AI assistant is connected to.

• Pros: It can be switched on and off in minutes and lets you start without disrupting your current setup, for example with unanswered calls only.
• Cons: Whether the caller's number reaches the assistant depends on the operator and the type of forwarding. Outbound calls from the assistant may show a different number. Ask your operator whether forwarded calls are charged to your line.

2. Connecting over a SIP trunk (BYOC)

A SIP trunk connects your business line to a phone system or call platform over the internet. With BYOC (bring your own carrier), your number and operator contract stay where they are; the only thing that changes is where calls are delivered. The connection is set up in one of two ways: registration-based, where the platform registers with the operator using a username and password, or IP-based, where the operator sends calls to specific IP addresses.

• Pros: Inbound and outbound calls use the same number, caller ID is passed through reliably, and the setup is permanent.
• Cons: Your operator has to offer SIP connections, and the number of channels on the line limits how many calls can run at once.

3. Number porting

Number porting moves your number from one operator to another. You apply to the new operator; once the number has moved, the line is managed from there.

• Pros: You work with a single provider.
• Cons: The process runs between operators and porting day needs planning; if you change your mind, going back means another port.

Which method fits you?

These are the most common starting points:

• Single-site business, calls come to a mobile: Start with forwarding. Forwarding on busy and on no answer keeps your phone ringing while the assistant picks up the calls you miss.
• Landline with an office PBX: BYOC is the most flexible route in the long run. During the transition, you can start by having the PBX send unanswered or after-hours calls to the assistant.
• Call center on an 0850 or 444 number: Ask the operator the number is set up with about SIP connections and channel counts; under heavy traffic BYOC behaves more predictably than forwarding.
• You want to leave your operator and work with one provider: Porting fits; test the new setup on a separate number before porting day.

Working alongside your existing PBX

Moving to an AI assistant does not mean removing your PBX straight away. There are two common setups: either the operator line reaches your PBX first and the PBX sends only certain calls (after hours, unanswered, a particular menu option) to the assistant, or the line reaches the AI platform first and calls that need a person land in a queue there. The first needs fewer changes during the transition; the second brings calls and reports into one place. We compare the two in detail in AI call center vs traditional PBX.

Architecture: where does a call go?

From the caller's phone to the voice agent, a call passes through these layers:

Caller (landline or mobile)
   │  public switched telephone network (PSTN)
   ▼
Your operator (where the number is set up)
   │  SIP trunk (BYOC) or call forwarding
   ▼
AI call platform
   │  call flow: business hours, IVR, KVKK notice, rules
   ├──► AI voice agent ──(if needed, with a summary)──┐
   │                                                  ▼
   └────────────────────────────────────────► Queue ──► Agent desk (browser, WebRTC)

Nothing changes for the caller: they dial the number they know. The call reaches your operator over the PSTN, and the operator delivers it to the platform over SIP. The platform's call flow sends it to the voice agent or straight to a queue, based on business hours and your rules. If the voice agent sees that the request needs a person, it hands the call to the queue with a summary of the conversation, and your operator picks it up from the desk in the browser.

Outbound calls take the reverse path: when the voice agent or an operator places a call, the platform sends it over the same SIP connection to your operator, which puts it on the phone network. With BYOC, the person you call sees your business's familiar number; in setups that rely on forwarding alone, outbound calls carry the number of the line the assistant is connected to. If you plan reminder or confirmation calls, this matters, because a customer who sees an unfamiliar number may hesitate to answer.

Steps for a switch without downtime

1. Take stock. List your numbers, each number's operator, your current PBX, existing forwarding rules and your business hours.
2. Choose a method. Decide on forwarding, BYOC or porting for each number, and ask your operator about SIP support.
3. Design the call flow. Define in-hours and after-hours branches, which calls the voice agent handles, handover rules and voicemail. If calls are recorded, put the KVKK notice at the start of the flow; see our greeting and after-hours announcement templates for wording.
4. Test on a separate number. Try the setup on a test number before connecting your main one.
5. Start gradually. At first, send only after-hours or unanswered calls to the new setup.
6. Plan a rollback. If something goes wrong, who switches forwarding off, and how? Write it down before switch-over day.
7. Switch at a quiet time. In the first hours, call from different carriers to confirm everything works.
8. Expand. As results come in, extend the scope to all calls and your other numbers.

Testing before you go live

• Call from different carriers, from both landlines and mobiles; does the call get through every time?
• Is the caller's number shown correctly on the platform?
• Which number does the other side see on outbound calls?
• Is the audio clear in both directions? One-way audio is the most common setup error.
• Are keypad presses recognised in the IVR menu?
• Do the after-hours branch, handover and voicemail work?
• When several calls come in at once, does any of them hit a busy tone?
• Are recordings and transcripts created?

To test the voice agent itself, use our 20-point checklist.

Common problems

Connecting your number in Speakline

In Speakline you can port your existing business number or keep using the line you have with your operator by connecting it over SIP (BYOC); your customers keep dialling the number they know. Inbound calls go to the voice agent or to queues in the call center, following the business hours, IVR menus and rules you set in the visual call flow designer. When needed, the voice agent hands the call over with a summary of the conversation, and your operators take it from the browser-based agent desk. If a recorded step in the call flow has no KVKK notice before it, the designer warns you.

We will work out which method suits your number together in an introductory call; get in touch.